1. Field of the Invention
The present invention relates to a packing device, and more particularly to an adhesive tape cutter.
2. Description of the Related Art
A conventional adhesive tape cutter 10, as shown in FIGS. 1.about.4, includes a handle 11 attached to a metal base plate 12 respectively secured to a cutting device 20 and a tape mounting 30 which carries thereon an adhesive tape roll 40. The cutting device 20 includes amounting piece 21 having an end fixed to base plate 12, a cutting edge 22 fixed to the mounting piece 21 and, a roller 23 having an end rotatably attached to the base plate 12. A positioning plate 24 fixes the free end of piece 21 and rotatably fixes the free end of roller 23 for mounting piece 21 and roller 23 on plate 12. A cooperating plate 13 provided on handle 11 is held beneath roller 23 and urged against roller 23 by a torsional spring (not shown) cooperates with roller 23 to form therebetween a clearance for passing therethrough the adhesive tape 41 from roll 40. In roller 23 presses tape 41 against the article to be applied with tape 41 and then edge 22 cuts tape 41 as desired.
Tape mounting 30 includes a shaft 31 having an end fixed to base plate 12 and a free end having a flattened portion 311. A carrier 32 is rotatably mounted on shaft 31 and carries thereon a roll 40. A positioner 33 which is coaxially adjustable and fixed into the shaft free end. A pressing piece 34, having an elongate hole 341, engages therein the flattened portion 311. A stopper 35 is sleeved on positioner 33. A spring 36 is mounted between pressing piece 34 and stopper 35 for biassing pressing piece 34 against carrier 32. A washer 37 is mounted between carrier 32 and pressing piece 34 and a sleeve 38 is mounted between carrier 32 and base plate 12.
Since spring 36 biasses piece 34 against carrier 32 through washer 37, tape roll 40 will have a rotational friction which results from the friction respectively occurring between washer 37 and pressing piece 34, washer 37 and carrier 32 and sleeve 38 and base plate 12. This rotational friction effects the tape-applying operation in that the rotational friction is of an enough magnitude, then the user can tightly, smoothly and perfectly apply the tape on the article to be tape-applied. Therefore, the user can neatly cut the tape so that the phenomena of a massed tape while the user is applying the tape on an article and an inadvertent tape slack while cutting the tape can be obviated.
Since sleeve 38, washer 37 and carrier 32 are plastic, even if positioner 33 is screwed into shaft 31 to the largest exent possible the rotational friction of tape roll 40 is still insufficient in that the plastic itself has a lubricating effect. In addition, sleeve 38, washer 37 and carrier 32 wear away relatively easily (since in practice, washer 37 and pressing piece 34 rarely relatively rotate) so that the rotational friction of tape roll 40 gradually reduces. Furthermore, if carrier 32 wears away to a serious extent, an entire new cutter 10 is needed since a carrier 32 cannot be independently obtained. Also, in continuous rapid packaging operation, the adhesive tape 41 easily escapes from the clearance between roller 23 and cooperating plate 13 (as shown in FIG. 4) to result in a massed tape which not only causes a waste in tape 41 and time, but is also troublesome.